heard the same story from someone who is close to Rav Avraham Yeshohua and he said that it was the Rogatchover who said the line makes sense as he is famous for a lot of similar lines in regards to mechabrei seforim.
also not sure if the op’s question is in regards to seforim or inspirational books – in my opinion there have been a lot of very good seforim that have been published within the last 20 years although many of the good ones are aggregations of previously published material.